Antitheft lock construction

ABSTRACT

THE PRESENT DISCLOSURE RELATES TO A SAFETY LOCK PLATE WHICH IS MOUNTED ON THE DOOR EDGE CONFRONTING THE JAMB AND WHICH IS FORMED WITH A RECTANGULAR OR OTHER SHAPED OPENING, THROUGH WHICH THE BOLT PASSES. INTEGRAL WITH THE PLATE AT ITS INNER EDGE PARALLEL TO THE JAMB IS A FLANGE WHICH IS BENT BACK TOWARD THE JAMB.

Sept; 20, 1971 :c. E. PALMER v ANTITHEFT LOCK CONSTRUCTION Filed June 16. 1969 INVI'JNI'OIL CHARLES E. PALMER BY 2 E WHI ATTORNEY United States Patent'O 3,606,429 ANTITHEFT LOCK CONSTRUCTION Charles E. Palmer, 10 Elizabeth St. 8., Port Credit, Ontario, Canada Filed June 16, 1969, Ser. No. 833,354 Int. Cl. E05b 15/02 US. Cl. 292-340 2 Claims ABSTRACT OF THE DISCLOSURE The present disclosure relates to a safety lock plate which is mounted on the door edge confronting the jamb and which is formed with a rectangular or other shaped opening, through which the bolt passes. Integral with the plate at its inner edge parallel to the jamb is a flange which is bent back toward the jamb.

The present invention relates to a safety antitheft lock construction which is designed to prevent unauthorized tampering with or opening of bevel shaped lock bolt.

It is among the objects of the present invention to provide a simple readily installed reliable safety antitampering lock plate of the character described in which there is assurance that the lock will be safe from tampering and in which unauthorized opening will be readily prevented.

Another object is to provide a simple device for overcoming unauthorized tampering with a lock bolt having a beveled face, normally used in snap lock doors or other swinging closures.

Still further objects and advantages will appear in the more detailed description set forth below, it being understood, however, that this more detailed description is given by way of illustration and explanation only and not by way of limitation, since various changes therein may be made by those skilled in the art without departing from the scope and spirit of the present invention.

In accomplishing the above objects it has been found most satisfactory, according to one embodiment of the present invention, to provide a readily mounted plate which will have a flange constituting an obstruction. This obstruction will prevent the insertion of a thin stiff plate or card to the extent which would enable it to force back or retract a lock bolt having a beveled end. The plate desirably is made in one piece and is mounted on the door edge confronting the jamb and is formed with a rectangular opening through which the bolt passes.

Integrally to the plate at the doors edge parallel to the jamb is a flange which is bent back toward the jamb. This flange constitutes an obstruction that will reliably prevent tampering and unauthorized opening of the lock.

A particular feature of the present invention resides in the fact that the flange is at the edge of the bolt opening, this being most effective in preventing an unauthorized opening thereof.

BRIEF DESCRIPTION OF THE DRAWINGS With the foregoing and other objects in view, the invention consists of the novel construction, combination and arrangement of parts as hereinafter more specifically described, and illustrated in the accompanying drawings, wherein is shown an embodiment of the invention, but it is to be understood that changes, variations and modifications can be resorted to which fall within the scope of the claims hereunto appended.

In the drawings wherein like reference characters denote corresponding parts throughout the several views:

FIG. 1 is a front perspective View showing the door with the lock plate in position.

FIG. 2 is a transverse sectional view upon the line 3,606,429 Patented Sept. 20, 1971 2-2 of FIG. 1, upon an enlarged scale as compared to FIG. 1.

FIG. 3 is a vertical transverse sectional View of the lock upon the line 3-3 of FIG. 2.

FIG. 4 is a side elevational view of the lock plate by itself.

Referring to FIGS. 1 to 4, there is shown the swinging door A which is hinged at the side B and provided with a snap lock C at the opposite side. The door is fitted in the jamb D, as shown best in FIG. 2, with the front face 20 of the door carrying the strip 21, the edge 22 of which is closely adjacent the edge 23 of the jamb B, leaving a narrow gap therebetween.

The lock 24, which is mounted in the recess 25 in the door, has a projecting latch member 26.with a flat rear face 27 and a beveled oblique curved face 28. The handle or knob 29 in FIG. 1 will withdraw the latch upon insertion of a key in the key Opening, which is not shown.

The present invention particularly relates to the tamperproof plate 44 having the flat portion 29 with the curved corners 30 and the inwardly bent portion 31. The plate has the openings 32 to enable the screws 33 to mount it on the inside face 46 of the jamb D. This plate has a rectangular opening 34, which, at its front edge 35, is provided with the inwardly directed flange 36.

This flange 36 is integral with the plate 29 and extends closely adjacent at its inner edge 37 to the edge 38 of the snap lock and to the edge 39 of the recess 40 in the jamb to receive the snap lock 26. The position of the flange is such that when it contacts the curved edge 28 it will normally prevent such curved edge from being forced inwardly in the direction 41, while the flange 36 will act to prevent any entry through the recess or crevice between 22 and 23 extending to the face 28 of the latch 26.

Such devices are indicated at 42 and it will be noted that they will be caught in the angle 43 before they can contact or force in the latch 26.

It is desirable that the angle between the flange 36 and the plate 29 be somewhat less than 90 and be between and 70, so that the insert 42 will always tend to slide down to the corner 43, preventing any contact between the edge of the plate 29 and the sloping curved beveled face of the latch 28. This will effectively prevent tampering.

It is noted that the plate 29, which is mounted adjacent the door edge confronting the jamb, will have its opening 34 serve also to reenforce the recess 40 in the jamb. The flange, by reason of its tendency to slope inwardly, tends to prevent any thin card or plate from being inserted into the latch 26 and causes it to slide into the corner. This will protect door locks having beveled faces, such as 28, from being subject to ready entry without a key by burglars or other unauthorized intruders. The flexibility of any insert plate 42 in itself will prevent, by contact with the sloping flange, any tendency toward opening the door latch.

The new latch plate or jamb plate, as shown in FIG. 4, can be readily substituted for present latch plates or jamb plates, and will effectively close the door.

As many changes could be made in the above antitheft lock construction, and many widely different embodiments of this invention could be made without departure from the scope of the claims, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.

Having now particularly described and ascertained the nature of the invention, and in what manner the same is to be performed, what is claimed is:

1. A safety device preventing unauthorized opening of a door snap lock of the type having an oblique projecting bolt facing forwardly, a swinging closure member provided with a knob and carrying said projecting bolt, a jamb having a recess to receive said projecting bolt, a lock mechanism operatively engaging said projecting bolt to permit said knob to actuate said bolt thereby enabling said closure member to be moved, said device including a strike plate mounted on said jamb at the position of the recess and having an opening corresponding with said recess, and a short flange projecting from said plate and at an angle to said plate in the range of 70 to 80 thereto forming a corner at the junction of said flange and said plate, said flange extending in the direction of said swinging closure member and located at and between the outer edge of the recess and the end of the oblique projecting bolt, whereby any insert placed between the door and the jamb and pushed inwardly will engage the flange and '2. The device of claim 1 further comprising a portion of said plate positioned inwardly of said door jamb and obliquely thereto.

References Cited UNITED STATES PATENTS ROBERT L. WOLFE, Primary Examiner US. Cl. X.R.'

be directed to said corner formed at the junction of said 15 70418; 292-34C flange and said plate. 

